According to the SAS theorem, if the 2 sides of the 2 triangles are multiples of each other by the same scale factor, with the angle in between them being the same for each triangle. The triangles are similar.
The SSS theorem is not appropriate here because we do not know the side lengths of AB or DE in the diagram. For SSS theorem we need to know all of the side lengths.
A is incorrect because the similarity can be determined.
